The "-before-init" target is intended to be like a "beforeRender" in Ext JS - a spot to do your thing before the build gets going. In this case it is the ideal place to override properties like these. These will be set to default values by the core "-init" target in .sencha/app/build-impl.xml (a good file to read):

When I try to access to the application from index.jsp, in development.js (line 22), the AJAX request which try to get bootstrap.json failed because the using path is http://localhost:8080/WEBSITE_ROOT/bootstrap.json instead of http://localhost:8080/WEBSITE_ROOT/touchApp/bootstrap.json.

I have followed the steps described in previous posts but this does not seem to work for me.
How should I proceed ?

That works great for production and testing. But now how do I develop? I am fooling with symlinks trying to shoehorn the workspace/app into my CMS module folder, but any success there breaks the production build css.